Light emitting apparatus

ABSTRACT

Provided is a light emitting apparatus. The light emitting apparatus includes a substrate; a light emitting device on the substrate; a fluorescent layer formed on the substrate and the light emitting device to surround the light emitting device; an encapsulant resin layer formed on the substrate and the fluorescent layer to surround the fluorescent layer; and a lens disposed on the light emitting device and supported by the substrate, wherein the lens includes a lens body having a first recess formed at a center of a top surface of the lens body and a second recess formed at a center of a bottom surface of the lens body, and a lens supporter provided at the bottom surface of the lens body to support the lens body such that the lens body is spaced apart from the substrate.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority of Korean Patent Application No.10-2009-0112479 filed on Nov. 20, 2009, which is hereby incorporated byreference in its entirety.

BACKGROUND

The present disclosure relates to a light emitting apparatus.

Light emitting devices such as light emitting diodes have advantages oflow power consumption, a long usable life cycle, and environmentalfriendly. Thus, the light emitting devices are being used for variouslight emitting apparatuses such as backlight units for electronicequipment, electronic displays, and lighting equipment.

In such a light emitting apparatus, an encapsulant resin layer is formedin various lens shapes to surround the light emitting device, therebyadjusting a distribution characteristic of light emitted from the lightemitting device.

SUMMARY

Embodiments provide a light emitting apparatus having a novel structure.

Embodiments also provide a light emitting apparatus including a lenshaving a novel structure.

Embodiments also provide a light emitting apparatus having a superiorlight emitting characteristic in a lateral direction.

In one embodiment, a light emitting apparatus comprises: a substrate; alight emitting device on the substrate; a fluorescent layer formed onthe substrate and the light emitting device to surround the lightemitting device; an encapsulant resin layer formed on the substrate andthe fluorescent layer to surround the fluorescent layer; and a lensdisposed on the light emitting device and supported by the substrate,wherein the lens includes a lens body having a first recess formed at acenter of a top surface of the lens body and a second recess formed at acenter of a bottom surface of the lens body, and a lens supporterprovided at the bottom surface of the lens body to support the lens bodysuch that the lens body is spaced apart from the substrate.

In another embodiment, a light emitting apparatus comprises: asubstrate; a light emitting device on the substrate; a fluorescentencapsulant layer formed on the substrate and the light emitting deviceto surround the light emitting device; and a lens disposed on the lightemitting device and supported by the substrate, wherein the lensincludes a lens body having a first recess formed at a center of a topsurface of the lens body and a second recess formed at a center of abottom surface of the lens body, and a lens supporter provided at thebottom surface of the lens body to support the lens body such that thelens body is spaced apart from the substrate.

The details of one or more embodiments are set forth in the accompanyingdrawings and the description below. Other features will be apparent fromthe description and drawings, and from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 2 are sectional views of a light emitting apparatusaccording to a first embodiment.

FIG. 3 is a sectional view of a light emitting apparatus according to asecond embodiment.

FIG. 4 is a sectional view of a light emitting device package in a lightemitting apparatus according to a third embodiment.

FIG. 5 is a sectional view of a light emitting device package in a lightemitting apparatus according to a fourth embodiment.

FIG. 6 is a sectional view of a light emitting device package in a lightemitting apparatus according to a fifth embodiment.

FIGS. 7 and 8 are views illustrating a light distribution characteristicof the light emitting apparatus according to the first embodiment.

DETAILED DESCRIPTION OF THE EMBODIMENTS

In the description of embodiments, it will be understood that when alayer (or film), region, pattern or structure is referred to as being‘on’ another layer (or film), region, pad or pattern, the terminology of‘on’ and ‘under’ includes both the meanings of ‘directly’ and‘indirectly’.

In the drawings, the thickness or size of each layer is exaggerated,omitted, or schematically illustrated for convenience in description andclarity. Also, the size of each element does not entirely reflect anactual size.

FIGS. 1 and 2 are sectional views of a light emitting apparatusaccording to a first embodiment.

Referring to FIGS. 1 and 2, a light emitting apparatus according to thefirst embodiment includes a substrate 10, a light emitting devicepackage 20 disposed on the substrate 10, and a lens 30 disposed on thesubstrate 10 above the light emitting device package 20 while beingsupported by the substrate 10.

The substrate 10 may be a printed circuit board (PCB). A circuit pattern(not shown) is disposed on the substrate 10, and the circuit pattern andthe light emitting device package 20 are electrically connected to eachother.

The light emitting device package 20 includes a package body 21, atleast one light emitting device 22 disposed on the package body 21, afluorescent layer 23 surrounding the light emitting device 22, and anencapsulant resin layer 24 surrounding the fluorescent layer 23 on thepackage body 21.

Electrode layers (not shown) are disposed on the package body 21. Theelectrode layers may pass through the package body 21 or may be disposedon a surface of the package body 21 to electrically connect the lightemitting device 22 to the circuit pattern of the substrate 10. Thepackage body 21 may be formed of various materials. For example, thepackage body 21 may be formed of one of a ceramic material, a resinmaterial, and a silicon material.

The light emitting device 22 may include a light emitting diode. Thelight emitting device 22 may be provided in plurality on the packagebody 21. In this embodiment, three light emitting devices 22 areprovided. The plurality of light emitting devices 22 may be connected toeach other in parallel or series. Also, the plurality of light emittingdevices 22 may be electrically connected to the electrode layers using aflip-chip method or a wire bonding method.

A light emitting diode emitting at least one of red light, green light,and blue light may be used as the light emitting device 22. In thisembodiment, the light emitting diode emitting the blue light isillustrated as an example.

The fluorescent layer 23 may surround the light emitting device 22 onthe package body 21. For example, the fluorescent layer 23 may contain ayellow luminescence material. The fluorescent layer 23 may have a flattop surface and a constant height on the package body 21.

The encapsulant resin layer 24 is disposed on the package body 21 tosurround the fluorescent layer 23. The encapsulant resin layer 24 may beformed of a transparent resin material, for example, an epoxy resin or asilicon resin.

The encapsulant resin layer 24 may have a convex structure at the centerof the top surface thereof. Also, the encapsulant resin layer 24 may beflat at a circumference of the top surface thereof.

The lens 30 includes a lens body 31 and a lens support 34 supporting thelens body 31. The lens body 31 and the lens support 34 may be integratedwith each other using an injection molding. Alternatively, the lens body31 and the lens support 34 may be provided as separate parts, and thencoupled to each other using an adhesive.

The lens body 31 may have an approximately circular shape when viewed ina plan view. A concavo-convex or roughness may be formed on a bottomsurface of the lens body 31. The concavo-convex section or a roughnessmay be formed on the bottom surface of the lens body 31 except for aregion where the second recess 33 is formed.

The lens support 34 may be provided in plurality on the bottom surfaceof the lens body 31. Although only two lens supports 34 are illustratedin this embodiment, the present disclosure is not limited thereto. Forexample, three or more lens supports 34 may be disposed spaced apartfrom each other to stably support the lens body 31. A configuration ornumber of the lens support 34 may be variously modified according to itsdesign.

The lens body 31 may be formed of a transparent resin material. Also,the lens body 31 may be spaced a predetermined distance from thesubstrate 10 by the lens support 34. The lens support 34 may be firmlyattached to the substrate 10 using an adhesive.

The lens body 31 has a protruding top surface on the whole. A downwardlyconcave first recessed part 32 is disposed at a central portion of thetop surface of the lens body 31. Also, the lens body 31 has a flatbottom surface. An upward concave second recessed part 33 is disposed ata central portion of the bottom surface of the lens body 31. The firstrecessed part 32 and the second recessed part 33 vertically overlap eachother.

Since the first recessed part 32 and the second recessed part 33 aredisposed at the central portion of the lens body 31, the lens body 31has a thin thickness at the central portion thereof. The lens body 31has a thickness which becomes gradually thicker from the central portiontoward an edge portion and then thinner again. Also, a circumference ofthe top surface of the lens body 31 may be flat, and a lateral surfaceadjacent to the bottom surface of the lens body 31 may be perpendicularto the bottom surface of the lens body 31.

The first recessed part 32 may have a maximum depth (a) of about 0.3 mmto about 0.4 mm. The second recessed part 33 may have a maximum depth(b) of about 2.5 mm to about 3 mm. Also, the first recessed part 32 mayhave a maximum width (c) of about 3.5 mm to about 4 mm. The secondrecessed part 33 may have a maximum width (d) of about 2.8 mm to about3.3 mm.

The lens support 34 may have a maximum thickness (e) of about 0.5 mm toabout 0.8 mm.

The lens body 31 may have a maximum thickness (h) of about 4 mm to about5 mm. A maximum thickness (f) from the bottom surface of the lens body31 to the flat top surface may range from about 1.8 mm to about 2 mm. Athickness (g) from the flat top surface of the lens body 31 to a topsurface may range from about 2.2 mm to about 2.8 mm.

The lens body 31 may have a maximum width (j) of about 13 mm to about 19mm. The lens body may have a maximum width (i) of about 12 mm to about18 mm at a portion in which the top surface of the lens body 31 iscurved.

In the light emitting device package 20, the package body 21 may have amaximum thickness of about 0.3 mm to about 0.4 mm, and a maximum heightfrom the top surface of the package body 21 to a top surface of theencapsulant resin layer 24 may range from about 1.1 mm to about 1.5 mm.

In this embodiment, a ratio (a/h) of the maximum depth (a) of the firstrecessed part 32 to the maximum thickness (h) of the lens body 31 mayrange from about 0.06 to about 0.1. A ratio (b/h) of the maximum depth(b) of the second recessed part 33 to the maximum thickness (h) of thelens body 31 may range from about 0.5 to 0.75. A ratio (b/a) of themaximum depth (b) of the second recessed part 33 to the maximum depth(a) of the first recessed part 32 may range from about 6.25 to about 10.

A ratio (c/j) of the maximum width (c) of the first recessed part 32 tothe maximum width (j) of the lens body 31 may range from about 0.18 toabout 0.3. A ratio (d/j) of the maximum width (d) of the second recessedpart 33 to the maximum width (j) of the lens body 31 may range fromabout 0.14 to about 0.25. A ratio (d/c) of the maximum width (d) of thesecond recessed part 33 to the maximum width (c) of the first recessedpart 32 may range from about 0.7 to about 0.94.

At least a portion of the encapsulant resin layer 24 is disposed withinthe second recessed part 33. The package body 21 has the maximumthickness less than that of the lens support 34. The bottom surface ofthe lens body 31 may be flush with the light emitting device 22 or thefluorescent layer 23 or flush with the encapsulant resin layer 24. Theencapsulant resin layer 24 may be completely separated from the lensbody 31.

As above-described, the light emitting apparatus has superior lightemitting efficiency in a lateral direction. Light emitted from the lightemitting device 22 is reflected and refracted by the encapsulant resinlayer 24 and reflected and refracted by the second recessed part 33 toemit a large amount of the light in the lateral direction. Specifically,the first recessed part 32 and the second recessed part 33 reduce anamount of light emitted in an upper direction.

FIGS. 7 and 8 are views illustrating a light distribution characteristicof the light emitting apparatus according to the first embodiment.

Referring to FIGS. 7 and 8, the light emitting apparatus according tothe first embodiment emits a peak light at an angle of about 70° toabout 85° or about −70° to about −85° when an angle perpendicular to thesubstrate 10 is defined as 0°. That is, it may be seen that the lightemitted from the light emitting apparatus is mainly emitted in thelateral direction.

Light emitting apparatuses according to second to seventh embodiments,which will be described below, have light distribution characteristicssimilar to light distribution characteristics of the light emittingapparatus shown in FIGS. 7 and 8.

FIG. 3 is a sectional view of a light emitting apparatus according to asecond embodiment.

In descriptions of a light emitting apparatus according to a secondembodiment, descriptions that duplicate those for the light emittingapparatus according to the first embodiment will be omitted.

Referring to FIG. 3, the light emitting apparatus according to a secondembodiment is formed through the COB (chip on board) method. The lightemitting device 22 is directly mounted on the substrate 10, and thefluorescent layer 23 is formed on the substrate 10 to surround the lightemitting device 22. In addition, the encapsulant resin layer 24 isformed on the substrate 10 to surround the fluorescent layer 23. Theencapsulant resin layer 24 comes into contact with the substrate 10 anda part of the encapsulant resin layer 24 is disposed in the secondrecessed part 33.

Different from the light emitting apparatus according to the firstembodiment, according to the second embodiment, the light emittingdevice 22 is directly mounted on the substrate 20 without being packagedby using the package body 21. Thus, the light generated from the lightemitting device 22 can be emitted with wider orientation angle and theheat generated from the light emitting device 22 can be effectivelydissipated to the outside.

FIG. 4 is a sectional view of a light emitting device package in a lightemitting apparatus according to a third embodiment.

In descriptions of a light emitting apparatus according to a thirdembodiment, descriptions that duplicate those for the light emittingapparatus according to the first and second embodiments will be omitted.The lens is omitted in FIG. 4.

Referring to FIG. 4, the light emitting apparatus according to a thirdembodiment is formed through the COB method. The light emitting device22 is directly mounted on the substrate 10, and the fluorescent layer 23is formed on the substrate 10 and the light emitting device 22 tosurround the light emitting device 22. In addition, the encapsulantresin layer 24 is formed on the substrate 10 and the fluorescent layer23 to surround the fluorescent layer 23. A part of the encapsulant resinlayer 24 is disposed in the second recessed part 33.

A concave part 10 a is formed in the substrate 10 and the encapsulantresin layer 24 is filled in the concave part 10 a. Therefore, a contactarea between the encapsulant resin layer 24 and the substrate 10 isincreased, so that the encapsulant resin layer 24 can be firmly coupledto the substrate 10 and the fluorescent layer 23.

FIG. 5 is a sectional view of a light emitting device package in a lightemitting apparatus according to a fourth embodiment.

In descriptions of a light emitting apparatus according to a fourthembodiment, descriptions that duplicate those for the light emittingapparatus according to the first and second embodiments will be omitted.

Referring to FIG. 5, the light emitting apparatus according to a fourthembodiment is formed through the COB method. The light emitting device22 is directly mounted on the substrate 10, and a fluorescentencapsulant layer 25 is formed on the substrate 10 and the lightemitting device 22 to surround the light emitting device 22.

The fluorescent encapsulant resin layer 25 is prepared in a convex shapeby dispensing an encapsulant resin layer including luminescencematerials distributed therein. The fluorescent encapsulant resin layer25 has the functions of the fluorescent layer and the encapsulant layer.Thus, the manufacturing process for the light emitting apparatusaccording to the fourth embodiment can be simplified.

FIG. 6 is a sectional view of a light emitting device package in a lightemitting apparatus according to a fifth embodiment.

In descriptions of a light emitting apparatus according to a fifthembodiment, descriptions that duplicate those for the light emittingapparatus according to the first and second embodiments will be omitted.The lens is omitted in FIG. 6.

Referring to FIG. 6, the light emitting apparatus according to a fifthembodiment is formed through the COB method. The light emitting device22 is directly mounted on the substrate 10, and the fluorescent layer 23having a predetermined thickness is formed on the substrate 10 and thelight emitting device 22 to surround the light emitting device 22. Inaddition, the encapsulant resin layer 24 is formed on the substrate 10and the fluorescent layer 23 to surround the fluorescent layer 23. Apart of the fluorescent layer 23 is disposed in the second recessed part33.

The fluorescent layer 23 is corrugated corresponding to theconfiguration of the light emitting device 22. That is, the fluorescentlayer 23 disposed on the substrate 10 has a height lower than that ofthe fluorescent layer 23 disposed on the light emitting device 22.According to the light emitting apparatus of the fifth embodiment, thefluorescent layer 23 having a predetermined thickness surrounds thelight emitting device 22, so that the color variation of the lightemitted from the light emitting apparatus can be diminished.

Any reference in this specification to “one embodiment,” “anembodiment,” “example embodiment,” etc., means that a particularfeature, structure, or characteristic described in connection with theembodiment is included in at least one embodiment of the invention. Theappearances of such phrases in various places in the specification arenot necessarily all referring to the same embodiment. Further, when aparticular feature, structure, or characteristic is described inconnection with any embodiment, it is submitted that it is within thepurview of one skilled in the art to effect such feature, structure, orcharacteristic in connection with other ones of the embodiments.

Although embodiments have been described with reference to a number ofillustrative embodiments thereof, it should be understood that numerousother modifications and embodiments can be devised by those skilled inthe art that will fall within the spirit and scope of the principles ofthis disclosure. More particularly, various variations and modificationsare possible in the component parts and/or arrangements of the subjectcombination arrangement within the scope of the disclosure, the drawingsand the appended claims. In addition to variations and modifications inthe component parts and/or arrangements, alternative uses will also beapparent to those skilled in the art.

1. A light emitting apparatus comprising: a substrate; a light emittingdevice on the substrate; a fluorescent layer formed on the substrate andthe light emitting device to surround the light emitting device; anencapsulant resin layer formed on the substrate and the fluorescentlayer to surround the fluorescent layer; and a lens disposed on thelight emitting device and supported by the substrate, wherein the lensincludes a lens body having a downwardly concave first recess formed ata center of a top surface of the lens body and an upwardly concavesecond recess formed at a center of a bottom surface of the lens body,and at least one of lens supporters provided at the bottom surface ofthe lens body to support the lens body such that the lens body is spacedapart from the substrate, and wherein a thickness of the lens bodybetween a bottom surface of the downwardly concave first recess and atop surface of the upwardly concave second recess increases from acenter region of one of the downwardly concave first recess or theupwardly concave second recess to an end region thereof, wherein a ratioof a maximum depth of the first recess to a maximum depth of the secondrecess is about 6.25 to
 10. 2. The light emitting apparatus of claim 1,wherein a ratio of a maximum depth of the first recess to a maximumthickness of the lens body is about 0.06 to 0.1, and a ratio of amaximum depth of the second recess to the maximum thickness of the lensbody is about 0.5 to 0.75.
 3. The light emitting apparatus of claim 1,wherein a ratio of a maximum width of the first recess to a maximumwidth of the lens body is about 0.18 to 0.3, and a ratio of a maximumwidth of the second recess to the maximum width of the lens body isabout 0.14 to 0.25.
 4. The light emitting apparatus of claim 1, whereina ratio of a maximum width of the first recess to a maximum width of thesecond recess is about 0.7 to 0.94.
 5. The light emitting apparatus ofclaim 1, wherein at least a part of the encapsulant resin layer isdisposed in the second recess.
 6. The light emitting apparatus of claim1, wherein the lens supporters are spaced apart from each other.
 7. Thelight emitting apparatus of claim 6, wherein the lens supporters havethree lens supporters.
 8. The light emitting apparatus of claim 1,wherein a peripheral portion of the top surface of the lens body isflat.
 9. The light emitting apparatus of claim 1, wherein the lenssupporter is bonded to the substrate.
 10. The light emitting apparatusof claim 1, wherein an entire top surface of the encapsulant resin layeris provided within the upwardly concave second recess.
 11. The lightemitting apparatus of claim 1, wherein the lens body has a thicknessbetween the top surface and the bottom surface that becomes thicker froma central portion toward an edge portion and then becomes thinner.
 12. Alight emitting apparatus comprising: a substrate; a light emittingdevice on the substrate; a fluorescent layer on the light emittingdevice to surround the light emitting device; an encapsulant resin layeron the fluorescent layer to surround the fluorescent layer; and a lenson the light emitting device and supported by the substrate, wherein thelens includes a lens body having a first recess and a second recess andat least one lens supporter, the first recess formed at a center of atop surface of the lens body and that extends toward a central portionof the lens body, and the second recess formed at a center of a bottomsurface of the lens body and that extends toward the central portion ofthe lens body, and wherein the first recess vertically overlaps thesecond recess, and the at least one lens supporter is provided at thebottom surface of the lens body to support the lens body such that thelens body is spaced from the substrate, and wherein a thickness of thelens body between a bottom surface of the first recess and a top surfaceof the second recess increases from a center region of one of the firstrecess or the second recess to an end region thereof, wherein a ratio ofa maximum depth of the first recess to a maximum depth of the secondrecess is about 6.25 to
 10. 13. The light emitting apparatus of claim12, wherein a ratio of a maximum depth of the first recess to a maximumthickness of the lens body is about 0.06 to 0.1, and a ratio of amaximum depth of the second recess to the maximum thickness of the lensbody is about 0.5 to 0.75.
 14. The light emitting apparatus of claim 12,wherein a ratio of a maximum width of the first recess to a maximumwidth of the lens body is about 0.18 to 0.3, and a ratio of a maximumwidth of the second recess to the maximum width of the lens body isabout 0.14 to 0.25.
 15. The light emitting apparatus of claim 12,wherein a ratio of a maximum width of the first recess to a maximumwidth of the second recess is about 0.7 to 0.94.
 16. The light emittingapparatus of claim 12, wherein an entire top surface of the encapsulantresin layer is provided within the second recess.
 17. The light emittingapparatus of claim 12, wherein the lens body has a thickness between thetop surface and the bottom surface that becomes thicker from a centralportion toward an edge portion and then becomes thinner.
 18. The lightemitting apparatus of claim 12, further comprising: the second recesshaving a first point at a center thereof, a second point at a first endof the second recess, a third point in between the first point and thesecond point, and a fourth point at a second end of the second recess,wherein the first recess having a fifth point at a center thereof, asixth point vertically aligned with the second point, and a seventhpoint in between the fifth point and the sixth point and beingvertically aligned with the third point; wherein the entire fluorescentlayer and the entire encapsulant resin layer are provided under thesecond recess that extends from the second point to the fourth point,wherein a first distance is the distance between the first point and thefifth point, a second distance is the distance between the third pointand the seventh point, and a third distance is the distance between thesecond point and the sixth point, and wherein the second distance isgreater than the first distance and the third distance is greater thanthe second distance.
 19. The light emitting apparatus of claim 1,wherein the downwardly concave first recess overlaps with the upwardlyconcave second recess in a vertical direction, the upwardly concavesecond recess having a first point at a center thereof, a second pointat a first end of the upwardly concave second recess, a third point inbetween the first point and the second point, and a fourth point at asecond end of the upwardly concave second recess, wherein the downwardlyconcave first recess having a fifth point at a center thereof, a sixthpoint vertically aligned with the second point, and a seventh point inbetween the fifth point and the sixth point and being vertically alignedwith the third point; wherein the entire fluorescent layer and theentire encapsulant resin layer are provided under the upwardly concavesecond recess that extends from the second point to the fourth point,wherein a first distance is the distance between the first point and thefifth point, a second distance is the distance between the third pointand the seventh point, and a third distance is the distance between thesecond point and the sixth point, and wherein the second distance isgreater than the first distance and the third distance is greater thanthe second distance.